3 replies to this topic

[Shaw]

Based on the work by phatomtypist on the "Bosch BMP085 digital pressure and temperature sensor" I have implemented a basic driver for the HMC5843.

A sample use:

        private static HMC5843 magSensor = new HMC5843(0x1E);

        public static void Main()
        {
            // Create a new I2C bus instance at startup.
            I2CBus i2cBus = I2CBus.Instance;

            magSensor.DirectionChanged += new HMC5843.DirectionChangedDelegate(magSensor_DirectionChanged);
            magSensor.StatusChanged += new HMC5843.StatusChangedDelegate(magSensor_StatusChanged);
            magSensor.ModeChanged += new HMC5843.ModeChangedDelegate(magSensor_ModeChanged);

            while (true)
            {
                magSensor.Start();
                Thread.Sleep(30000);

                magSensor.Stop();
                Thread.Sleep(30000);
            }
       }

        static void magSensor_ModeChanged(HMC5843.ModeBits mode)
        {
            Debug.Print("Mode Changed to " + mode.ToString());
            if (mode == HMC5843.ModeBits.Idle || mode == HMC5843.ModeBits.Sleep)
            {
                LED.Write(false);
            }
            else
            {
                LED.Write(true);
            }
         } 

        static void magSensor_StatusChanged(HMC5843.StatusBits status)
        {
            Debug.Print("Status Changed to " + status.ToString());
            
        }

        static void magSensor_DirectionChanged(short X, short Y, short Z)
        {
            Debug.Print("XYZ = " + X + ", " + Y + ", " + Z);
        }

Attached Files

•  HMC5843.cs   8.99KB   55 downloads

[Michel Trahan]

            I2CBus i2cBus = I2CBus.Instance;

Which I2CBus implementation are you using ... it refuses to compile due to missing ".Instance" ...

[BitFlipper]

    magSensor.DirectionChanged += new HMC5843.DirectionChangedDelegate(magSensor_DirectionChanged);

As a bit of a simplification, the above can be re-written like this:

    magSensor.DirectionChanged += magSensor_DirectionChanged;

I'm not sure why VS still insists on using the long-form format, but I always remove the extraneous code afterwards.

Another way to clean up code a bit:

    I2CBus i2cBus = I2CBus.Instance;

...can be rewritten as:

    var i2cBus = I2CBus.Instance;

I find that it cleans up the code nicely, especially if you have a long list of local variables.

[ScottyG]

Can someone help me as how to wire this (HMC5843)up and a general getting started? It looks simple but I cannot find a thing except for the Honeywell HMC5843 specification. Thanks,